package com.transaction.utils;

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.nio.ByteBuffer;
import java.nio.channels.FileChannel;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Map;

import javax.crypto.Cipher;

/**
 * <p>
 * RSA公钥/私钥/签名工具包
 * 
 * </p>
 */
public class RSAUtils {

	/**
	 * 加密算法RSA
	 */
	public static final String KEY_ALGORITHM = "RSA";

	/**
	 * 签名算法
	 */
	public static final String SIGNATURE_ALGORITHM = "SHA1WithRSA";

	/**
	 * 获取公钥的key
	 */
	private static final String PUBLIC_KEY = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCTe96q+L0xDhWpKa/VbZ3HjAaJVYmOyU35WFoFT5KBCAlAOSlA11+kf8vC2a9vEQV02oNHtWaX7VCCNDZfm0wcrkiB4k3/HQypVKAD9dcIy0ICvqaNrLSHFY3HgKqboC33bFRs3IvPtWi0tOHe0uzk16xfv9fvIHC1wUk66qAeCwIDAQAB";

	/**
	 * 获取私钥的key
	 */
	private static final String PRIVATE_KEY = "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";

	/**
	 * RSA最大加密明文大小
	 */
	private static final int MAX_ENCRYPT_BLOCK = 117;

	/**
	 * RSA最大解密密文大小
	 */
	private static final int MAX_DECRYPT_BLOCK = 128;

    /**
	 * <p>
	 * 生成密钥对(公钥和私钥)
	 * </p>
	 * 
	 * @return
	 * @throws Exception
	 */
	public static Map<String, Object> genKeyPair() throws Exception {
		KeyPairGenerator keyPairGen = KeyPairGenerator
				.getInstance(KEY_ALGORITHM);
		keyPairGen.initialize(1024);
		KeyPair keyPair = keyPairGen.generateKeyPair();
		RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
		RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
		Map<String, Object> keyMap = new HashMap<String, Object>(2);
		keyMap.put(PUBLIC_KEY, publicKey);
		keyMap.put(PRIVATE_KEY, privateKey);
		return keyMap;
	}

	/**
	 * <p>
	 * 用私钥对信息生成数字签名
	 * </p>
	 * 
	 * @param data
	 *            已加密数据
	 * @param privateKey
	 *            私钥(BASE64编码)
	 * 
	 * @return 签名结果为base64字符串
	 * @throws Exception
	 */
	public static String sign(byte[] data, String privateKey) throws Exception {
		byte[] keyBytes = Base64Utils.decode(privateKey);
		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
		signature.initSign(privateK);
		signature.update(data);
		return Base64Utils.encode(signature.sign());
	}

	/**
	 * <p>
	 * 用私钥对信息生成数字签名
	 * </p>
	 * 
	 * @param data
	 *            已加密数据
	 * @param privateKey
	 *            私钥
	 * 
	 * @return 签名结果为base64字符串
	 * @throws Exception
	 */
	public static String sign(byte[] data, PrivateKey privateKey)
			throws Exception {
		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
		signature.initSign(privateKey);
		signature.update(data);
		return Base64Utils.encode(signature.sign());
	}

	/**
	 * 私钥文件读取
	 * 
	 * @param privateKeyFile
	 * @return
	 */
	public static PrivateKey fileToPrivateKey(String privateKeyFile) {
		File key = new File(privateKeyFile);
		try {
			FileInputStream is = new FileInputStream(key);
			FileChannel channel = is.getChannel();
			byte[] buffer = new byte[is.available()];
			channel.read(ByteBuffer.wrap(buffer));
			byte[] keyBytes = Base64Utils.decode(new String(buffer));
			PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
			KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
			PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
			return privateK;
		} catch (Throwable e) {
			e.printStackTrace();
			return null;
		}
	}

	/**
	 * 私钥文件读取（带AES加密）
	 * 
	 * @param privateKeyFile
	 * @return
	 */
	public static PrivateKey fileToPrivateKey(String privateKeyFile,
			String password) {
		File key = new File(privateKeyFile);
		try {
			FileInputStream is = new FileInputStream(key);
			FileChannel channel = is.getChannel();
			byte[] buffer = new byte[is.available()];
			channel.read(ByteBuffer.wrap(buffer));
			byte[] keyBytes = AESUtils.decrypt(new String(buffer), password);
			PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
			KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
			PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
			return privateK;
		} catch (Throwable e) {
			e.printStackTrace();
			return null;
		}
	}

	/**
	 * 公钥文件读取
	 * 
	 * @param publicKeyFile
	 * @return
	 */
	public static PublicKey fileToPublicKey(String publicKeyFile) {
		File cert = new File(publicKeyFile);
		try {
			FileInputStream is = new FileInputStream(cert);
			FileChannel channel = is.getChannel();
			byte[] buffer = new byte[is.available()];
			channel.read(ByteBuffer.wrap(buffer));
			byte[] keyBytes = Base64Utils.decode(new String(buffer));
			X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
			KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
			PublicKey publicK = keyFactory.generatePublic(keySpec);
			return publicK;
		} catch (Throwable e) {
			e.printStackTrace();
			return null;
		}
	}
	
	public static PublicKey dbToPublicKey(String publicKey) {
		try{
			byte[] keyBytes = Base64Utils.decode(publicKey);
			X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
			KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
			PublicKey publicK = keyFactory.generatePublic(keySpec);
			return publicK;
		} catch (Throwable e) {
			e.printStackTrace();
			return null;
		}
	}

	/**
	 * <p>
	 * 校验数字签名
	 * </p>
	 * 
	 * @param data
	 *            已加密数据
	 * @param publicKey
	 *            公钥(BASE64编码)
	 * @param sign
	 *            数字签名(BASE64编码)
	 * 
	 * @return
	 * @throws Exception
	 * 
	 */
	public static boolean verify(byte[] data, String publicKey, String sign)
			throws Exception {
		byte[] keyBytes = Base64Utils.decode(publicKey);
		X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		PublicKey publicK = keyFactory.generatePublic(keySpec);
		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
		signature.initVerify(publicK);
		signature.update(data);
		return signature.verify(Base64Utils.decode(sign));
	}

	/**
	 * <p>
	 * 校验数字签名
	 * </p>
	 * 
	 * @param data
	 *            已加密数据
	 * @param publicKey
	 *            公钥
	 * @param sign
	 *            数字签名(BASE64编码)
	 * 
	 * @return
	 * @throws Exception
	 * 
	 */
	public static boolean verify(byte[] data, PublicKey publicKey, String sign)
			throws Exception {
		Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
		signature.initVerify(publicKey);
		signature.update(data);
		return signature.verify(Base64Utils.decode(sign));
	}

	/**
	 * <P>
	 * 私钥解密
	 * </p>
	 * 
	 * @param encryptedData
	 *            已加密数据
	 * @param privateKey
	 *            私钥(BASE64编码)
	 * @return
	 * @throws Exception
	 */
	public static byte[] decryptByPrivateKey(byte[] encryptedData,
			String privateKey) throws Exception {
		byte[] keyBytes = Base64Utils.decode(privateKey);
		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
		cipher.init(Cipher.DECRYPT_MODE, privateK);
		int inputLen = encryptedData.length;
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		int offSet = 0;
		byte[] cache;
		int i = 0;
		// 对数据分段解密
		while (inputLen - offSet > 0) {
			if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
				cache = cipher
						.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
			} else {
				cache = cipher
						.doFinal(encryptedData, offSet, inputLen - offSet);
			}
			out.write(cache, 0, cache.length);
			i++;
			offSet = i * MAX_DECRYPT_BLOCK;
		}
		byte[] decryptedData = out.toByteArray();
		out.close();
		return decryptedData;
	}

	/**
	 * <p>
	 * 公钥解密
	 * </p>
	 * 
	 * @param encryptedData
	 *            已加密数据
	 * @param publicKey
	 *            公钥(BASE64编码)
	 * @return
	 * @throws Exception
	 */
	public static byte[] decryptByPublicKey(byte[] encryptedData,
			String publicKey) throws Exception {
		byte[] keyBytes = Base64Utils.decode(publicKey);
		X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		Key publicK = keyFactory.generatePublic(x509KeySpec);
		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
		cipher.init(Cipher.DECRYPT_MODE, publicK);
		int inputLen = encryptedData.length;
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		int offSet = 0;
		byte[] cache;
		int i = 0;
		// 对数据分段解密
		while (inputLen - offSet > 0) {
			if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
				cache = cipher
						.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
			} else {
				cache = cipher
						.doFinal(encryptedData, offSet, inputLen - offSet);
			}
			out.write(cache, 0, cache.length);
			i++;
			offSet = i * MAX_DECRYPT_BLOCK;
		}
		byte[] decryptedData = out.toByteArray();
		out.close();
		return decryptedData;
	}

	/**
	 * <p>
	 * 公钥加密
	 * </p>
	 * 
	 * @param data
	 *            源数据
	 * @param publicKey
	 *            公钥(BASE64编码)
	 * @return
	 * @throws Exception
	 */
	public static byte[] encryptByPublicKey(byte[] data, String publicKey)
			throws Exception {
		byte[] keyBytes = Base64Utils.decode(publicKey);
		X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		Key publicK = keyFactory.generatePublic(x509KeySpec);
		// 对数据加密
		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
		cipher.init(Cipher.ENCRYPT_MODE, publicK);
		int inputLen = data.length;
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		int offSet = 0;
		byte[] cache;
		int i = 0;
		// 对数据分段加密
		while (inputLen - offSet > 0) {
			if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
				cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
			} else {
				cache = cipher.doFinal(data, offSet, inputLen - offSet);
			}
			out.write(cache, 0, cache.length);
			i++;
			offSet = i * MAX_ENCRYPT_BLOCK;
		}
		byte[] encryptedData = out.toByteArray();
		out.close();
		return encryptedData;
	}

	/**
	 * <p>
	 * 私钥加密
	 * </p>
	 * 
	 * @param data
	 *            源数据
	 * @param privateKey
	 *            私钥(BASE64编码)
	 * @return
	 * @throws Exception
	 */
	public static byte[] encryptByPrivateKey(byte[] data, String privateKey)
			throws Exception {
		byte[] keyBytes = Base64Utils.decode(privateKey);
		PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
		KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
		Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
		Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
		cipher.init(Cipher.ENCRYPT_MODE, privateK);
		int inputLen = data.length;
		ByteArrayOutputStream out = new ByteArrayOutputStream();
		int offSet = 0;
		byte[] cache;
		int i = 0;
		// 对数据分段加密
		while (inputLen - offSet > 0) {
			if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
				cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
			} else {
				cache = cipher.doFinal(data, offSet, inputLen - offSet);
			}
			out.write(cache, 0, cache.length);
			i++;
			offSet = i * MAX_ENCRYPT_BLOCK;
		}
		byte[] encryptedData = out.toByteArray();
		out.close();
		return encryptedData;
	}

	/**
	 * <p>
	 * 获取私钥
	 * </p>
	 * 
	 * @param keyMap
	 *            密钥对
	 * @return
	 * @throws Exception
	 */
	public static String getPrivateKey(Map<String, Object> keyMap)
			throws Exception {
		Key key = (Key) keyMap.get(PRIVATE_KEY);
		return Base64Utils.encode(key.getEncoded());
	}

	/**
	 * <p>
	 * 获取公钥
	 * </p>
	 * 
	 * @param keyMap
	 *            密钥对
	 * @return
	 * @throws Exception
	 */
	public static String getPublicKey(Map<String, Object> keyMap)
			throws Exception {
		Key key = (Key) keyMap.get(PUBLIC_KEY);
		return Base64Utils.encode(key.getEncoded());
	}
	
	/**
	 * 
	 * @Title:getSkPrivateKey
	 * @Description:
	 * @param: @return
	 * @author:kyn
	 * @time 2018年7月26日 下午2:57:10
	 * @return PrivateKey
	 * @throws
	 */
	public static PrivateKey getSkPrivateKey() {
		try {
			PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(Base64Utils.decode(PRIVATE_KEY));
			KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
			PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
			return privateK;
		} catch (Exception e) {
			e.printStackTrace();
		}
		return null;
		
	}

}